Air-bag deployment bias apparatus

Abstract: A new and improved apparatus for biasing the direction of air-bag deployment includes a box-shaped guide member (40), preferably of fabric construction, and attached to an air-bag module (24) and folded to overlie a folded air-bag (30). The box-shaped guide member (40) has an open bottom and is erected to the box shape upon deployment of the air-bag (30) through an air-bag opening (18). The box-shaped guide member (40) has an open end wall at the inboard side thereof to define a lateral deployment opening through which the air-bag (30) may be deployed laterally, and a top deployment opening through which the air-bag (30) may deploy upwardly and rearwardly towards a seat occupant. The box-shaped guide member (40) also includes a top flap (50) which selectively closes off the top deployment opening of the guide member (40) to bias and divert the deploying air-bag (30) through the lateral opening until the top flap (50) is unfolded to an extended position opening the top opening to permit the further deployment of the air-bag (30) through the top opening.

Description: This invention relates to a vehicle having an air-bag and inflation apparatus as specified in the preamble of claim 1. It is well-known in motor vehicles to provide an air-bag assembly which is mounted beneath an opening in the instrument panel. A door closes the air-bag deployment opening and is moved from a closed position to an open position by the deploying air-bag. The prior art has recognised that the deployment of an air-bag towards an occupant seating position is dependent upon factors such as the size and shape of the air-bag, the placement of tethers inside the air-bag to control the deployed shape of the air-bag, the magnitude and duration of inflation pressure and the placement of vent openings in the air-bag. The prior art has also recognised that an external deployment mechanism may be employed to control the deployment of an air-bag (EP-A-0 453 740). An apparatus in a vehicle according to the present invention, is characterised by the features specified in the characterising portion of claim 1. The present invention provides a new and improved apparatus for biasing the direction of air-bag deployment. According to the invention, a box-shaped guide member, preferably of fabric construction, is attached to an air-bag module and is folded to overlie a folded air-bag. The box-shaped guide member has an open bottom and is erected to the box shape upon deployment of the air-bag through an air-bag opening. The box-shape has an open end wall at the inboard side thereof to define a lateral deployment opening through which the air-bag may be deployed laterally, and a top deployment opening through which the air-bag may deploy upwardly and rearwardly towards an occupant of a seat in a motor vehicle in which the air-bag is mounted. The box-shape also includes a top flap which selectively closes off the top deployment opening of the box to bias and divert the deploying air-bag through the lateral opening until the top flap is unfolded to an extended position opening the top opening to permit the further deployment of the air-bag through the top opening. Accordingly, the object, feature and advantage of the invention resides in the provision of an air-bag biasing mechanism which is operative, when held in a horizontal folded position, to initially deploy the air-bag in a lateral direction and then to permit further deployment of the air-bag in an unbiased upward and rearward direction towards said occupant. These and other features, objects and advantages of the invention will be apparent upon consideration of the description of the preferred embodiments of the invention and the accompanying drawings, in which: Figure 1 is a perspective view of a vehicle body instrument panel showing an inflating air-bag assembly biased by a biasing apparatus according to one embodiment of this invention; Figure 2 is a enlarged perspective view showing the biasing apparatus of Figure 1; Figure 3 is a cross-sectional view taken in the direction of Arrows 3--3 of Figure 1, showing the folding of the air-bag biasing apparatus on top of a folded air-bag; Figure 4 is a cross-sectional view taken in the direction of Arrows 4--4 of Figure 3, showing the folding of the air-bag biasing apparatus; Figure 5 is a view similar to Figure 2, but showing a second embodiment of the invention; Figure 6 is a view similar to Figures 2 and 5, but showing a third embodiment of the invention; Figure 7 is a view similar to Figure 2 but showing a fourth embodiment of the invention; Figure 8 is an elevational view in cross-section, showing the folding of the biasing apparatus of Figure 7 in solid line, and the progressive unfolding of the biasing apparatus in phantom line; and Figure 9 is a view similar to Figure 1, but showing the air-bag biasing apparatus of this invention used in conjunction with an air-bag mounted on a rearward face of the instrument panel. Referring to Figure 1, it is seen that a motor vehicle includes an instrument panel structure 10 located forwardly of an occupant seating compartment 12 and bounded by a windshield 14. A rectangularly-shaped air-bag deployment opening 18 is provided in a top surface of the instrument panel 10 and a glove box opening 20 is provided on the rear facing wall of the instrument panel. As best seen in Figure 2, an air-bag module assembly 24 is mounted beneath the instrument panel 10 and includes a sheet-metal housing 26 enclosing an inflator 28. An air-bag 30, sewn of suitable fabric material, is suitably attached within the housing 26 and is normally folded to lie on top of the inflator 28. Figures 1 and 2 show the air-bag having been inflated by inflation gas generated by the inflator 28, which in turn causes the air-bag to deploy upwardly through the air-bag opening 18. The air-bag opening 18 is normally closed by an air-bag door 34 which is suitably hingedly attached to the instrument panel 10 and is opened upwardly towards the windshield 14 by the deploying air-bag 30. As seen in the drawings, the present invention provides a biasing apparatus, generally indicated at 40, which functions to control the direction of air-bag inflation. More particularly, it is seen that the inflation biasing apparatus 40 is comprised of a box-shaped construction of fabric or other flexible, foldable material and includes a forward wall 42 and a rearward wall 44 which are connected together by an end wall 46 connecting the outboard edges of the forward wall 42 and the rearward wall 44. The box-shape is open at an inboard end thereof opposite the end wall 46 as defined by the space between the forward wall 42 and the rearward wall 44. The end wall 46 has an extended top flap portion 50 which extends upwardly beyond the dimensional extent of the forward and rearward walls 42 and 44 so that a top flap portion 50 has a folded condition shown in Figures 1 and 2 and an open, extended position shown in phantom line in Figure 2. As seen in the drawings, the bottommost edges of the box-shape, including the bottom edge of the forward wall 42, the bottom edge of the rearward wall 44 and the bottom edge of the end wall 46 are suitably attached to the air-bag module 24 outside of the attachment of the air-bag 30 to the module 24 so that the biasing apparatus 40 can be folded on top of the folded air-bag. Accordingly, when the air-bag is deployed through the air-bag opening 18 on the instrument panel, the biasing apparatus 40 is pushed through the opening ahead of the air-bag, causing the forward wall 42, rearward wall 44 and end wall 46 to be erected generally vertically as shown in Figures 1 and 2, thereby defining a deployment chute. During some air-bag deployments, depending upon the position of the occupant, the top flap portion 50 may be held at the horizontal position of Figures 1 and 2 by either the air-bag door 34 or by the occupant. When the top flap portion 50 is held at this horizontal position, the deploying air-bag is biased leftwardly (as seen in Figure 1) through the open inboard end of the biasing apparatus 40 so that the bag 30 inflates more inboard of the occupant than would result in those deployments in which the top flap portion 50 is moved to the fully-open, phantom-line position of Figure 2. When the top flap portion 50 reaches the fully-open position, the air-bag deploys in the conventional unbiased upward and rearward direction towards the occupant. It will be appreciated that the extent and duration of the biasing effect may be varied by controlling the relative size and shape of the forward wall 42, rearward wall 44, end wall 46 and the top flap portion 50 of the biasing apparatus 40. Figures 3 and 4 show the manner in which the biasing apparatus 40 is folded on top of the air-bag module 24. In particular, Figure 3 shows that the forward wall 42 is pleated inwardly at 43 and the rearward wall 44 is pleated inwardly at 45 to meet at the centre of the air-bag module 24. Figure 4 shows that the outboard end wall 46 is also pleated inwardly at 47. This inward pleating of the walls 42, 44 and 46 has the effect of shortening the height of the walls. Accordingly, the remaining unpleated height portion of the end wall 46 can be folded to lie on top of the air-bag module 24. Then, the remaining height of the rearward wall 44 is laid on top of the end wall 46. Finally, the remaining height of forward wall 42 is folded down on top of the rearward wall 44. This particular folding arrangement has been found to provide effective biasing of the air-bag, although it is recognised that alternative folding arrangements could be employed and may be desirable and effective depending upon variables such as the size, shape, location and construction of the various elements of the air-bag assembly, the vehicle and the occupant seating position. Figure 5 shows a second embodiment of the invention in which the biasing apparatus, designated 140, has a forward wall 142 and a rearward wall 144 which are more trapezoidal in shape to meld into the height of an end wall 146 and its top flap portion 150. Figure 6 shows yet another embodiment of the invention in which the biasing apparatus, designated 240, includes only a rearward flap 244 and an outboard flap 246 with its top flap 250. This embodiment of the invention omits use of a forward wall as had been employed in the embodiments of Figures 2 and 5. In the absence of a forward wall, the maintenance of a force on the top flap 150 holding the flap 150 downwardly will permit the air-bag to inflate against the windshield while also biasing the inflation in the leftward direction (as seen in Figure 6) inboard of an occupant through the open end wall. Figures 7 and 8 show a fourth and further simplified embodiment of the invention in which the biasing apparatus, designated 340, has only an outboard end wall 346 and a top flap portion 350. The solid-line position of Figure 8 shows the biasing apparatus 340 with a portion of its end wall 346 pleated inwardly at 352 so that the top flap 350 is folded on top of the pleated portion 352 and a folded air-bag 330. As the air-bag 330 deploys upwardly from an air-bag module 324, the biasing apparatus 340 is deployed upwardly to a phantom-line position designated "A" in which the pleat 352 has been removed and the end wall 346 has been erected. However, the top wall 350 is shown to remain at its folded position by either the deployment door or the occupant, so that the deploying air-bag will be biased to deploy in the leftward direction, as viewed in Figure 8. Figure 8 also shows a phantom-line position "B" in which the top flap 350 has unfolded to its upright position so that the biasing effect is removed from the air-bag 330 and the air-bag is permitted to continue deploying free of the biasing effect applied by the biasing apparatus 340. It will be appreciated that, in each embodiment of the invention, the inward pleating of the end wall to overlie the air-bag defines a deployment chute structure in which the deploying air-bag will unfold the pleat from the end wall and lift the top flap bodily upwards away from the air-bag module when the top flap is held in the horizontal or near-horizontal position by either the air-bag door or the presence of an occupant. Thus, it is seen that the invention provides apparatus effective when held down in a horizontal position for biasing the deployment of an air-bag laterally of the occupant position, at least during the initial stage of air-bag deployment. The eventual inflation of the air-bag will progressively move the air-bag door 34 and/or the occupant away from holding down the top flap portion 50 so that the top flap portion 50 can rise to the vertical position and then the air-bag inflates in an unbiased fashion. Although Figure 1 of the drawings shows the air-bag opening disposed on a top surface of the instrument panel, it should be understood that the air-bag opening can be located in the rear face of the instrument panel, as shown in Figure 9, or in a low mount position, even lower than the position shown in Figure 9. The air-bag deployment apparatus, designated 440, will advantageously bias air-bag 430 deployment inboard of the occupant, in the event the occupant position holds an air-bag biasing top flap 450 on top of the air-bag 430. Each of the embodiments shown in the drawings biases the air-bag deployment in a direction laterally inboard of a respective seat occupant. However, the biasing apparatus can also be reoriented to bias the air-bag in a laterally outboard direction relative to a respective seat occupant.

Claims: Apparatus for selectively initiating the deployment of an air-bag (30) laterally relative to a seated occupant in a vehicle in which the air-bag (30) is stored in a folded condition forwardly of the seated occupant and is deployable, by the introduction of pressurised inflation gas into the air-bag (30), to an occupant-restraining position relative to the seated occupant, characterised in that the apparatus includes a deployment guide member (40) having a normal stored position overlying the folded air-bag (30) and which is deployable toward the occupant by the deploying air-bag (30), said guide member (40) having at least an end wall (46) pleated inwardly to lie on top of the folded air-bag (30), and a top flap (50) hingedly connected to the end wall (46) and folded to lie on top of the pleated end wall (46) in a closed top position so that initial deployment of the air-bag (30) unpleats the end wall (46) and permits the top flap (50) to shift towards the occupant and then bias initial deployment of the air-bag (30) laterally relative to the occupant when the top flap (50) is held in a folded position, until the eventual unfolding of the top flap (50) permits subsequent unbiased deployment of the air-bag (30) towards the occupant. Apparatus according to claim 1, in which the air-bag (30) is stored beneath a vehicle instrument panel (10) and is deployable through an opening (18) in the panel (10), wherein the deployment guide member (40) is formed of flexible foldable material and includes a rearward wall (44) and a side wall (42) attached to the vehicle and folded on top of the folded air-bag (30) so that the rearward and side walls (42,44) are deployed through the panel opening (18) ahead of the deploying air-bag (30) to define an air-bag deployment chute having a lateral deployment opening opposite the end wall (46) and a top deployment opening which registers with the panel opening (18) of the instrument panel (10); said end wall (46) having said top flap portion (50) extending beyond the dimensional extent of the rearward wall (44) and being folded on top of the folded air-bag (30) in the stored position so that the flap portion (50) closes the top opening of the chute to bias the air-bag deployment through the lateral opening until the flap portion (50) is unfolded to an extended position opening the top opening of the chute to permit further deployment of the air-bag (30) through the top opening. Apparatus according to claim 2, in which the lateral deployment opening is positioned at the end of the side and rearward walls (42,44) opposite the end wall (46). Apparatus according to claim 1, in which the air-bag (30) is stored beneath a vehicle panel (10) and is deployable through an opening (18) in the panel (10); wherein the deployment guide member (140) is deployable through the panel opening (18) by the deploying air-bag (30); said guide member (140) having a box shape with an open bottom admitting the deploying air-bag (30) and forward, rearward and outboard side walls (142,144,146) deployable from the stored position on top of the folded air-bag (30) to a deployed position; the top flap (150) being hingedly connected to the outboard side wall (146) for movement between the closed top position and an open top position, and there is an open inboard side to the guide member (140) through which the air-bag (30) obtains initial deployment laterally of the occupant when the top flap (150) is held in the closed top position.

Inventors: HAWTHORN LAURA ADELLE, HAWTHORN, LAURA ADELLE
Applicants: GEN MOTORS CORP, GENERAL MOTORS CORPORATION
Application year: 1994
Main classification: B60R21
IPC codes: B60R21